Title :
Curie temperatures and dielectric properties of doped and undoped KTiOPO/sub 4/ and isomorphs
Author :
Chu, David K T ; Hsiung, Hui ; Cheng, Lap Kin ; Bierlein, John D.
Author_Institution :
E.I. du Pont de Nemours Co., Wilmington, DE, USA
Abstract :
The Curie temperatures and dielectric properties of KTiOPO/sub 4/ (KTP), RbTiOPO/sub 4/, KTiOAsO/sub 4/, RbTiOAsO/sub 4/, CsTiOAsO/sub 4/, Ba:KTP, and Ga:KTP were measured with small-signal relative dielectric permittivity ( kappa ) analysis, piezoelectric resonance analysis, and optical second harmonic generation. All the isomorphs and the doped KTP exhibit lower Curie temperatures than KTP, ranging from 637 degrees C for CsTiOAsO/sub 4/ to 955 degrees C for hydrothermally (HT) grown KTP. The Curie-Weiss law is obeyed in all samples. With the exception of CsTiOAsO/sub 4/, all doped and undoped crystals show large dielectric relaxation at frequencies below 100 KHz throughout the temperature range of 500 degrees C-800 degrees C. For the barium-doped KTP, it was found that the Curie temperature decreases with increasing Ba/sup ++/-doping concentration. Barium doping also significantly modifies dielectric and piezoelectric properties of KTP.<>
Keywords :
barium; caesium compounds; dielectric properties of solids; dielectric relaxation; doping profiles; ferroelectric Curie temperature; ferroelectric materials; gallium; optical harmonic generation; permittivity; piezoelectric materials; potassium compounds; rubidium compounds; 500 to 800 C; 637 to 955 C; CsTiOAsO/sub 4/; Curie temperatures; Curie-Weiss law; KTiOAsO/sub 4/; KTiOPO/sub 4/:Ba; KTiOPO/sub 4/:Ga; RbTiOAsO/sub 4/; RbTiOPO/sub 4/; dielectric properties; dielectric relaxation; doping concentration; hydrothermal growth; isomorphs; optical second harmonic generation; piezoelectric properties; piezoelectric resonance analysis; small-signal relative dielectric permittivity; undoped crystals; Barium; Crystals; Dielectric measurements; Frequency; Harmonic analysis; Nonlinear optics; Optical harmonic generation; Permittivity measurement; Resonance; Temperature distribution;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
